Laser cutting is a kind of high energy and density control good non-contact processing way.
After focusing laser beam with high energy density of light, applied in cutting has many characteristics.
And there are four main laser cutting cutting in different ways, in order to cope with different situations.
Melt in laser fusion cutting, cutting workpiece after partial melting with the aid of the molten material ejected.
Because the material transfer occurs only in the case of the liquid, so the process is called the laser fusion cutting.
A laser beam with high purity inert gas cutting force molten material away from the slot, and gas by itself is not involved in cutting.
The laser fusion cutting can get higher cutting speed than gasification cutting.
The energy for the gasification is generally higher than the energy for the melt material.
In laser fusion cutting, the laser beam is only absorbed by part.
The most * big cutting speed increased with the increase of laser power, with the increase of thickness and material melting temperature almost inverse proportion to the increase of decrease.
Under the condition of the laser power must, limiting factor is the cutting seam pressure and thermal conductivity of materials.
Laser fusion cutting material for iron and titanium metal can be obtained without oxidation incision.
Produce gasification and melting but is less than the laser power density, for steel materials, in the 104 w/cm2 ~ 105 w/cm2.
Vaporization cutting in laser gasification cutting process, the material surface temperature to the boiling point temperature speed is so fast, enough to avoid melting caused by heat conduction, so part of the material vaporized into steam, part of the material as the ejecta from the bottom of the kerf width auxiliary gas flow blown away.
This case need to be very high laser power.
In order to prevent material to steam condensation slotted walls, the thickness of the material must not be larger than the diameter of the laser beam.
The processing and therefore only suitable for application in the case of exclude melting materials must be avoided.
The processing, in fact, only for the use of iron base alloy is small area.
Cannot be used in the processing, such as wood and some ceramics, those without melting state and therefore is unlikely to let material vapor condensation of materials.
In addition, these materials to achieve more often thick incision.
In the laser vaporization cutting, beam focus depends on the material thickness and beam quality.
Laser power and the gasification hot focus position only certain influence.
In the case of plate thickness must be, cutting speed is in the gasification temperature of the material.
The laser power density is greater than 108 w/cm2, and depends on the material, cutting depth and the beam focus position.
Under the condition of the plate thickness must be, assuming that there is enough of laser power, cutting speed is limited by a gas jet speed.
Fracture cutting for easy to control heat damage of brittle materials, high speed, controlled by laser beam heating cutting, called control fracture cutting.
The cutting process is the main content: laser beam heating brittle material is small area, causing the area of thermal gradient and severe mechanical deformation, cracks leads to the formation of a material.
Laser beam may guide so long as you keep balanced heating gradient cracks in any direction.
Oxidation melting cutting (
Laser flame cutting)
Melt cutting generally use inert gases, if replaced with oxygen or other reactive gas, was lit materials under the irradiation of laser beam, and the chemical reaction of oxygen violent and produce another source of heat, make further heating material, called oxidation melting cutting.
Due to the effect, for the same thickness of the steel, the method can be used to get the cutting rate is higher than melting cutting.
On the other hand, this method is compared with fusion cutting may be poorer quality of incision.
In fact, it will generate more wide slot, roughness, obvious increase of heat affected zone and the edge of the worse quality.
Laser flame cutting on the machining precision model and Angle is bad (
There is a risk of burning Angle)
Can use of laser pulse mode to limit the thermal effect, the laser power decided to cutting speed.
Under the condition of the laser power must, limiting factor is the supply of oxygen and thermal conductivity of materials.